Fast pyrolysis reactor for organic biomass materials with against flow injection of hot gases

ABSTRACT

The main purpose of the invention is a fast pyrolysis reactor ( 1 ) with entrained flow of biomass organic particles ( 2 ), comprising a reaction chamber ( 3 ), a device ( 4 ) for injection of particles ( 2 ) in the upper part ( 3   a ) of the reaction chamber ( 3 ), to form a flow (FG) of particles ( 2 ) dropping by gravity, an evacuation duct ( 5 ) for products originating from the pyrolysis reaction present in the reaction chamber ( 3 ), characterized in that it also comprises a counter current hot neutral gases injection duct  6  in the lower part ( 3   b ) of the reaction chamber ( 3 ) making it possible to form a counter current flow (FG) of hot neutral gases coming into contact with the flow (FG) of particles ( 2 ) dropping by gravity, the temperature of the hot neutral gases being between 500 and 600° C., and the diameter of the particles ( 2 ) being between 200 μm and 1 mm.

TECHNICAL DOMAIN

This invention relates to the general domain of pyrolysis, particularly fast pyrolysis, process in which solid organic materials are heated to high temperatures in an oxygen depleted environment to form other products, including gases and solid and liquid material in vapor form (condensable at low temperature).

Preferably, the invention is applied to fast pyrolysis of biomass organic materials, including all organic materials with plant, animal or fungal origin, particularly to obtain pyrolytic oil and pyrolytic coke that can be used for example as fuels. In particular, the invention can be used for the production of pyrolytic oil for partial or total substitution of fossil fuels, for example used in a boiler.

The invention thus discloses a fast pyrolysis reactor for biomass organic particles with counter current injection of hot neutral gases that come into contact with particles dropping by gravity, a fast pyrolysis installation for biomass organic particles comprising such a reactor, and an associated process for fast pyrolysis of biomass organic particles.

STATE OF PRIOR ART

Pyrolysis is a well known process in which organic compounds are heated to high temperatures, for example from 300° C. to 1000° C., in a low oxygen or zero oxygen environment to prevent oxidation and combustion. Under these conditions, the material dehydrates and is then subjected to thermolysis, in other words a thermal breakdown. Thus, pyrolysis usually results in three types of compounds, namely pyrolysis coke or pyrolytic coke also called “char”, pyrolysis oil or pyrolytic oil, and gases, particularly incondensable gases, for example carbon monoxide (CO), carbon dioxide (CO₂), dihydrogen (H₂), methane (CH₄), and others.

Two approaches to pyrolysis can be envisaged, namely slow pyrolysis and fast pyrolysis, and three temperature ranges can be envisaged, namely low, high or very high temperature.

For slow pyrolysis at low temperature, the material is heated to a moderate temperature, namely between 400 and 500° C., thus requiring a longer residence time, usually between 10 and 60 minutes, to maximize the yield of solid material. These conditions favor the production of pyrolytic coke to the detriment of pyrolytic vapors, and therefore pyrolytic oil.

Conversely, fast pyrolysis takes place at high temperature, typically between 500 and 600° C., during a residence time of between 1 and 10 seconds, and generates mainly pyrolytic vapors, to obtain pyrolytic oil to the detriment of pyrolytic coke and incondensable gases. Fast pyrolysis at very high temperature (more than 800° C.) is conducive to the production of incondensable gases.

More specifically, much work has been done over several years on the fast pyrolysis of wood and as a result, several types of industrial pyrolysis processes have been created.

The principle of fast pyrolysis of wood is based on the application of a very high heat flux to the wood, typically more than 10⁵ W.m⁻², to cause fast heating and degradation of the wood. When this pyrolysis takes place at around 500° C., the majority products of the degradation are pyrolytic condensable vapors forming pyrolytic oil that are cooled as quickly as possible and then collected, typically after a few seconds, to prevent them from reacting and producing gases. The pyrolytic obtained can then be used as a fuel because it has a calorific value of the order of 16 MJ/kg. Special burners will then have to be used if it is to be burned, due to its specific properties and particularly its viscosity.

Most industrial process for the fast pyrolysis of wood according to prior art are based on the use of boiling or circulating fluidized beds. Examples include fluidized beds made by the Canadian Dynamotive Energy Systems company, fluidized beds made by the American Ensyn company, the rotating cone made by the Dutch BTG BioLiquids company, and ablative pyrolysis. Details of these types of process can be found in the following reviews—“Review of fast pyrolysis of biomass and product upgrading>>, A. V Bridgewater, Biomass and bioenergy, 38 (2012), 68-94; and “A review of recent laboratory research and commercial developments in fast pyrolysis and upgrading”, E. Butler et al, Renewable and sustainable Energy Reviews, 15 (2011), 4171-4186.

Nevertheless, industrial processes known in prior art are relatively complex to implement, and require qualified personnel. Medium or large installations are also necessary to achieve sufficient cost effectiveness, with production of one to several tens of tonnes per hour.

Consequently, there is a need to disclose a moderately size fast pyrolysis reactor based on a simple and robust technology, that produces primarily pyrolytic oil, for use on a local scale.

The entrained flow reactors (EFR) technology is known for second generation biofuel production installations. These reactors are intended for use in very large installations with a production of between 50 and 100 tonnes per hour, operating at high pressure typically from 30 to 80 bars, and at high temperature of about 1500° C. These reactors are used for gasification of organic compounds to maximize gas production.

If it is required to maximize production of pyrolytic oil with this type of entrained flow reactor, the operating temperature needs to be about 500° C. and the operating pressure needs to be close to atmospheric pressure, to have a device with a simplified design.

However, very few solutions are described in prior art for the production of pyrolytic oil with an entrained flow reactor. Thus, the principal known installations are two fast pyrolysis pilot plants using an entrained flow reactor, namely the installation designed by the American Georgia Tech Research Institute (GTRI), and the installation developed by the Belgian Egemin company.

The GTRI installation, designed for a biomass flow of 50 kg/h, is described in patent U.S. Pat. No. 4,891,459 A and is also mentioned in the “The Georgia Tech entrained flow pyrolysis process—Pyrolysis and gasification>>publication” Kovac and O'Neil, Elsevier applied science (1989), 159-179. In this installation, particles are injected into the bottom of the reactor and products obtained are collected at the top of the reactor. Heating is done by an external burner supplied by propane, so that a very hot gas at about 927° C. can be mixed with the flow of injected particles.

The Egemin installation designed for a biomass flow of 200 kg/h is mentioned for example in the “The Egemin flash pyrolysis process: commissioning and initial results” publication, Maniatis, K et al, Advance in thermochemical biomass conversion (1994), 1257-1264. In this installation, heating is done by an internal burner supplied by propane so that the gas can be heated to about 700° C., with nitrogen dilution to prevent the temperature from rising too high.

In the two installations described above, the pyrolytic reactor designed to operate at between 400 and 600° C. is not isothermal, such that good control over the reaction is not possible and consequently yields obtained are low, at between 40 and 60%. Furthermore, the size grading of the particles used, up to 1.5 and 2.5 mm, makes it impossible for them to reside in the reactor sufficiently long to be heated internally so they can be completely converted. Consequently, the unsuitable particle size leads to low pyrolytic oil yields.

PRESENTATION OF THE INVENTION

Thus, there is a need to disclose a new type of fast pyrolysis reactor for biomass organic particles, to optimize production of pyrolytic oil by optimizing heat transfer to biomass particles.

The purpose of the invention is to at least partially remedy the needs mentioned above and the disadvantages in embodiments according to prior art.

The purpose of one aspect of the invention is a fast pyrolysis reactor with entrained flow of biomass organic particles, including:

-   -   a tubular reaction chamber in which the particle pyrolysis         reaction takes place, including an upper part and a lower part,         opposite the upper part,     -   particle injection device in the upper part of the reaction         chamber, to form a flow of particles dropping by gravity in the         reaction chamber,     -   an evacuation duct for products originating from the pyrolysis         reaction and present in the reaction chamber, including gases         and pyrolyzed particles designed particularly to form pyrolytic         oil, pyrolytic coke also called “char” and incondensable gases,         characterized in that it comprises     -   a duct for counter current injection of hot neutral gases into         the lower part of the reaction chamber, to form a counter         current flow of hot neutral gases coming into contact with the         flow of particles dropping by gravity so as to generate the fast         pyrolysis reaction of particles and particularly to enable a         loss of mass, specifically 60% for each particle, causing a         reduction of their density so that they can be re-entrained by         the hot gases, during which the fast pyrolysis reaction         continues and terminates as they rise, the temperature of the         hot neutral gases being between 500 and 600° C., and the         diameter of the particles being between 200 μm and 1 mm.

Advantageously, the generated pyrolysis gases rising with the gas flow have a minimum residence time, which prevents them from being modified by thermal cracking.

With the invention, it may be possible to obtain a new type of fast pyrolysis reactor for biomass organic particles to satisfy the needs mentioned above. In particular, the reactor obtained has a simplified design. Heat exchanges can also be improved by counter current operation thus facilitating fast pyrolysis. The counter current flow can also entrain gases immediately that they are produced, and particularly condensable gases, such that their residence time is short. This advantageously prevents thermal modification of the condensable vapors to less desirable “secondary” tars. In other words, it is possible to keep so-called “primary” condensable vapors better than with solutions according to prior art in which the residence time of gases is longer. Energy integration of the reactor according to the invention may also be possible by exploitation of incondensable gases. Char can also be used in the process either as a combustible product alone or mixed with pyrolysis oil.

The fast pyrolysis reactor according to the invention may also comprise one or several of the following characteristics taken in isolation or in any possible technical combination.

Advantageously, the evacuation duct may open up in the upper part of the reaction chamber to evacuate products derived from the pyrolysis reaction in the reaction chamber, since these products migrate to the upper part of the reaction chamber.

The particle diameter will preferably be between 200 μm and 800 μm.

Furthermore, the particle injection device may include a particles reservoir containing particles and located outside the reaction chamber, a tubular particle injector located in the upper part of the reaction chamber, and means of transporting particles originating from the reservoir to the tubular injector.

The diameter of the tubular injector may be less than the diameter of the reaction chamber.

Particle transport means may be of any type, and may for example comprise a worm screw system, a vibrating belt system, among other systems.

The reactor may also comprise means of injecting an entrainment gas in the upper part of the reaction chamber, particularly in the tubular injector of the injection device, to improve particle injection into the reaction chamber.

Another purpose of another aspect of the invention is an installation for fast pyrolysis of biomass organic particles, characterized in that it comprises:

-   -   a pyrolysis reactor like that defined above,     -   a burner upstream from the reactor, configured to produce hot         neutral gases circulating in the hot neutral gases counter         current injection duct,     -   a separator downstream from the reactor, configured to enable         separation of pyrolytic coke and the flow of condensable and         incondensable gases,     -   a condenser downstream from the separator, configured to enable         separation of pyrolytic oil and the flow of incondensable gases,

The installation may also comprise means of injection of a first part of the incondensable gases flow output from the condenser into the boiler after heating by combustion of this first part of the incondensable gases flow.

The installation may also comprise means of injection of a second part of the incondensable gases flow output from the condenser to a burner heat exchanger to form hot neutral gases circulating in the hot neutral gases counter current injection duct, heat being produced from the burner supplied by the first part of the incondensable gases flow.

The installation may also comprise a first heat exchanger placed upstream from the condenser, to preheat the second part of the incondensable gases flow output from the condenser.

Another purpose of another aspect of the invention is a process for fast pyrolysis of biomass organic particles, characterized in that it makes use of a fast pyrolysis reactor as defined previously or a fast pyrolysis installation as defined previously, and that it comprises the step for counter current injection of hot neutral gases into the reaction chamber of the reactor in the direction opposite to the direction of particles dropping by gravity, on which the fast pyrolysis reaction will take place.

The process may be implemented making use of a fast pyrolysis installation like that defined above, and it may include the step consisting of using incondensable gases output from the condenser to heat hot neutral gases circulating in the hot neutral gases counter current injection duct and/or to form the hot neutral gases circulating in the hot neutral gases counter current injection duct.

The process may also comprise the step to inject an entrainment gas into the reactor reaction chamber, to improve particle injection into the reaction chamber.

The process may also comprise the step to use pyrolytic coke as fuel to add heat, particularly for heating the entrainment gas.

The process may also include the step to add a heat exchanger between the separator and the condenser to enable heat recovery.

The process may also include the step to use pyrolytic coke mixed with pyrolytic oil to produce a fuel.

The fast pyrolysis reactor, the fast pyrolysis installation and the fast pyrolysis process according to the invention may comprise any one of the characteristics mentioned in the description, taken in isolation or in any technically possible combination with other characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understand by reading the following detailed description of a non-limitative example embodiment of the invention, and an examination of the diagrammatic and partial figures in the appended drawing on which:

FIG. 1 shows a diagram illustrating an example fast pyrolysis reactor according to the invention,

FIG. 2 illustrates the size grading of particles used in the reactor in FIG. 1 in graphic form, with a Rosin-Rammler type of distribution representing the percentage of particles as a function of their diameter,

FIGS. 3A, 3B and 3C illustrate the trajectory of biomass particles, the gas temperature and the molar fraction of water vapor in the reaction chamber respectively, for a first configuration of the reactor in FIG. 1,

Ia FIG. 4 represents the change in the fraction by mass of non-pyrolyzed dry material in the particles in a first configuration the reactor in FIG. 1, as a function of time,

FIGS. 5A, 5B and 5C illustrate the trajectory of biomass particles, the gas temperature and the molar fraction of water vapor in the reaction chamber respectively, for a second configuration of the reactor in FIG. 1,

Ia FIG. 6 represents the change in the fraction by mass of non-pyrolyzed dry material in the particles in a second configuration the reactor in FIG. 1, as a function of time,

FIG. 7 shows a diagram illustrating an example fast pyrolysis installation according to the invention, comprising the fast pyrolysis reactor in FIG. 1.

In all these figures, identical references can designate identical or similar elements.

Furthermore, the different parts shown on the figures are not necessarily all at the same scale, to make the figures more easily understandable.

DETAILED PRESENTATION OF A PARTICULAR EMBODIMENT

Note that throughout the description, the terms upper and lower should be considered relative to the vertical direction, the direction along which particles drop under the effect of the earth's gravity. In particular, the upper part of the reaction chamber is located above the lower part of the reaction chamber. In other words, the upper part is the top part of the chamber, and the lower part is the bottom part of the chamber. Moreover, the terms upstream and downstream should be considered relative to the normal flow direction of the flow considered (from upstream to downstream), in particular the gas flow and/or particles flow.

With reference to FIG. 1, the figure diagrammatically shows an example embodiment of a reactor 1 according to the invention for fast pyrolysis of biomass organic particles 2.

The biomass organic particles 2 may be of any type, they may be made of organic materials with plant, animal and/or fungal origin. They may be in the form of a powder of biomass particles 2.

Thus, the reactor 1 comprises firstly a tubular reaction chamber 3 in which the pyrolysis reaction of particles 2 occurs.

This reaction chamber 3 is formed from a main cylindrical body 3 c at the ends of which are the upper part 3 a and the lower part 3 b of the reaction chamber 3. These upper 3 a and lower 3 b parts have a tapered shape. However, the invention is not limited to this type of shape. As a variant, the upper 3 a and lower 3 b parts may have a cylindrical shape, particularly they may have the same diameter as the main cylindrical body 3 c.

Furthermore, the reactor 1 comprises a device 4 for injection of particles 2 into the upper part 3 a of the reaction chamber 3.

This injection device 4 comprises a reservoir 4 a or hopper 4 a of particles 2, containing particles 2 on which the pyrolysis reaction will be carried out in the reaction chamber 3. This reservoir 4 a is located outside the reaction chamber 3.

The injection chamber 4 also comprises a tubular injector 4 c injecting particles 2 into the reaction chamber 3, enabling injection of a stable and known flow of particles 2.

This tubular injector 4 c is located in the upper part 3 a of the reaction chamber 3. It is present near the top, followed by a cylindrical shape in the lower part in which particles 2 are ejected. The diameter Di of the cylindrical part of the tubular injector 4 c is advantageously less than the diameter Dr of the cylindrical body 3 c of the reaction chamber 3. The outlet nozzle of the tubular injector 4 c may advantageously be fitted with a particle detector enabling a wider distribution of particles in the reactor. Furthermore, the useful height of the reaction chamber 3 is defined so as to achieve a sufficiently long drop time of the particles 2 for the pyrolysis reaction on them to be completed.

Moreover, the injection device 4 comprises transport means 4 b for particles 2 output from the reservoir 4 a to the tubular injector 4 c, external to the reaction chamber 3. These transport means 4 b may be of any type. In the example shown, they consist of a worm screw. As a variant, they could also be formed for example from a vibrating belt.

The injection of particles 2 through the injection device 4 into the reaction chamber 3 can then form a flow of particles 2 dropping by gravity FG into the reaction chamber 4, so as to allow the particles 2 to pass through an upper part of the reaction chamber 3 and before its lower part 3 b.

When the particles 2 are injected into the tubular injector 4 c, injection means N of an entrainment gas, for example nitrogen, are placed in the tubular injector 4 c of the injection device 4 so as to improve and aid the injection of particles 2 into the reaction chamber 3. The injection of such a neutral entrainment gas also inerts the distribution of particles 2 towards the reaction chamber 3 and thus prevents return of pyrolysis gas to the injection device 4.

Furthermore, the reactor 1 also comprises an evacuation duct 5 opening up in the upper part 3 a of the reaction chamber 3 through which products derived from the pyrolysis reaction in the reaction chamber 3 can be evacuated, these products being entrained towards the upper part 3 a of the reaction chamber 3 and containing gases, forming a flow of condensable and incondensable gases FR and pyrolyzed particles 2′ that will form pyrolytic oil, incondensable gases and pyrolytic coke called “char”, respectively.

Moreover, the reactor 1 also comprises a hot neutral gases counter current injection duct 6 in the lower part 3 b of the reaction chamber 3, to obtain a fast pyrolysis reaction with entrained counter-current flow.

This counter current injection duct 6 makes it possible to form a counter current flow FC of hot neutral gases coming into contact with the flow of particles 2 dropping by gravity FG, so as to generate the fast pyrolysis reaction of the particles 2.

The temperature of these hot neutral gases forming the counter current flow FC is preferably between 500 and 600° C., while the diameter of the particles 2 contained in the flow of particles 2 dropping by gravity FG is preferably between 200 μm and 1 mm, advantageously between 200 μm and 800 μm.

The flow of hot gases forming the counter current flow FC and the diameter Dr of the main body 3 c of the reaction chamber 3 are calculated such that the velocity of hot gases is high enough to entrain pyrolyzed particles 2′ to the upper part 3 a of the reaction chamber 3.

The pyrolysis reaction inside the reaction chamber 3 takes place as described below. When the particles 2 in the flow FG dropping by gravity meet the hot gases in counter current flow FC, these particles 2 are heated and lose their residual water. The pyrolysis reaction starts when the particles 2 reach a temperature of about 300° C. The particles 2 then continue to be heated until they come into temperature equilibrium with the hot gases that are cooled. Starting at the beginning of the pyrolysis reaction, the particles 2 release condensable and incondensable gases forming the gas flow FR. The particles 2 thus lose a large proportion of their volume and their mass, particularly of the order of 85% at a temperature of about 500° C. to 550° C., 70% of the mass being converted into condensable gases that will form pyrolysis oil and 15% into incondensable gases. The particle density 2 then becomes low and starting from a given flow of hot gases, the then pyrolyzed particles 2′ are entrained towards the top of the reactor 1 in its upper part 3 a with the flow of condensable and incondensable gases FR to be evacuated through the evacuation duct 5.

For example, with a reaction chamber 3 comprising a main body 3 c with diameter Dr equal to about 20 cm and height Hr equal to about 3.6 m, a flow of biomass particles 2 equal to about 10 kg/h and a flow of hot gases in the counter current flow FC of the order of 80 Nm³/h, the velocity of hot gases obtained is of the order of 2 m/s such that almost 95% of particles 2 with a diameter of between 0.1 and 1 mm, are pyrolyzed.

Different simulations were made using the Fluent fluid dynamics simulation software to evaluate operation of the fast pyrolysis reactor 1 according to the invention.

We thus considered a biomass particles flow 2 of the order of 10 kg/h, these particles 2 being wood particles with a moisture content of 7% and having a Rosin-Rammler distribution type of size grading relative to the diameter Dp of the particles 2, represented on FIG. 2. These particles 2 thus have an average diameter of the order of 0.500 mm, a minimum diameter of the order of 0.350 mm and a maximum diameter of the order of 1 mm.

Moreover, it was considered that the reaction chamber 3 comprises a main body 3 c with diameter Dr of the order of 20 cm, its walls being adiabatic. The diameter Di of the tubular injector 4 c is of the order of 5 cm.

The biomass particles 2 are also injected using an entrainment gas in the form of nitrogen at a velocity of the order of 0.1 m/s and at a temperature of about 27° C. The counter current flow FC comprises nitrogen injected at about 550° C.

Two configurations were simulated and optimized as a function of the height Hr of the main body 3 c of the reaction chamber 3 and the injection velocity of the counter current flow FC.

First Configuration

In the first configuration, the height Hr of the main body 3 c of the reaction chamber 3 is 3.6 m, while the injection velocity of the counter current flow FC is 1 m/s.

Two indicators are defined to quantify the performance of the reactor 1:

-   -   the pyrolysis ratio τ_(p) that is the ratio between the mass         flow of pyrolysis products obtained and the mass flow of         injected dry biomass particles, namely:     -   τ_(p)=[mass flow of pyrolysis products obtained/mass flow of         injected biomass particles],     -   the yield r_(g) of uncracked tars that is the ratio between the         flow of uncracked tars obtained and the flow of tars obtained         ideally with complete hydrolysis in the absence of cracking,         namely:     -   r_(g)=[flow of uncracked tars obtained/flow of tars obtained         ideally with a complete hydrolysis in the absence of cracking].

Thus, in this first configuration with injection of the counter current flow FC at 1 m/s and height Hr of the main body 3 c of the reaction chamber 3 equal to 3.6 m, the biomass particles 2 are pyrolyzed with a ratio τ_(p) equal to 99%, while the yield of uncracked tars r_(g) is 98%.

Thus, pyrolysis is practically complete and the yield of uncracked tars is very close to maximum, since the cracking rate is low. This means that the primary tars exit from the reactor 1 unchanged and can therefore be recovered, namely condensed, in the form of pyrolytic oil.

FIGS. 3A, 3B and 3C illustrate the trajectory of biomass particles, the gas temperature expressed in Kelvin (K) and the molar fraction of water vapor in the reaction chamber 3 respectively, in the reactor 1, Furthermore, FIG. 4 represents the change in the mass fraction Fm of non-pyrolyzed dry material in the particles 2, as a function of the time t expressed in seconds.

It is thus observed that practically all the particles 2, after drying and pyrolysis, are evacuated through the top of the reaction chamber 3 in the form of char. Only the largest particles 2 do not rise and stay at the bottom of the chamber 3 with less complete pyrolysis. Thus, 93% of the outlet mass of the particles is evacuated from the top, the remaining 7% being collected at the bottom. Moreover, the cold zone of the reaction chamber 3 is located at the top of the chamber. Furthermore, water vapor rises immediately after it is produced by the particles 2.

Furthermore, the height Hr of 3.60 m has been optimized for an injection velocity of the counter current flow FC equal to 1 m/s. This means that the yield of the reactor 1 cannot be improved by increasing the height. Conversely, a lower height would reduce this yield.

Second Configuration

In the second configuration, the height Hr of the main body 3 c of the reaction chamber 3 is 3 m, while the injection velocity of the counter current flow FC is 1.5 m/s.

FIGS. 5A, 5B and 5C illustrate the trajectory of biomass particles, the gas temperature expressed in Kelvin (K) and the molar fraction of water vapor in the reaction chamber 3 respectively, in the reactor 1, Furthermore, FIG. 6 represents the change in the mass fraction Fm of non-pyrolyzed dry material in the particles 2, as a function of the time t; expressed in seconds.

We thus observed that increasing the injection velocity of the counter current flow FC to 1.5 m/s has two advantages: with an injection velocity of 1.5 m/s, all particles 2 exit through the top of the reaction chamber 3 except for a very small proportion;

moreover, the height of the optimized reaction chamber 3 is modified to 3 m. On the other hand, the performance of the reactor 1 is not as good since the pyrolysis ratio τ_(p) is 88% and the yield r_(g) of uncracked tars is 87%.

We will now refer to FIG. 7 to describe an installation 10 for fast pyrolysis of biomass organic particles 2 comprising a fast pyrolysis reactor 1 like that described previously with reference to FIG. 1.

As can be seen on this FIG. 7, in addition to the reactor 1, the installation 10 comprises a burner 11 including a heat exchanger E located upstream from the reactor 1 and configured to produce hot gases forming the counter current flow FC circulating in the hot gases counter current injection duct 6.

Furthermore, the installation 10 comprises a separator 12 (or cyclone) forming a filtration device, placed downstream from the reactor 1 and configured to enable the separation of pyrolytic coke C, or char C, by filtration at a temperature higher than 250° C., and a condensable and incondensable gases flow FR′ starting from products originating from the pyrolysis reaction in the reaction chamber 3, including a condensable and incondensable gases flow FR at temperature TR of the order of 400° C. and pyrolyzed particles 2′.

Furthermore, the installation 10 also comprises a condenser 14 placed downstream from the separator 12 and configured to enable the production of pyrolytic oil H and an incondensable gases flow FR″ starting from the condensable and incondensable gas flow FR′ output from the separator 12. The temperature in this condenser 14 is preferably as low as possible, particularly of the order of 0° C. for an industrial process.

Advantageously, the installation includes energy integration of the incondensable gases flow FR″ with the formation of a closed circuit to improve the performance of the fast pyrolysis process.

In particular, the installation 10 comprises injection means in the form of a first circulating pump Ci₁ to inject a first part FR″₁ of the incondensable gases flow FR″ output from the condenser 14 to the burner 11 after this first part FR″₁ has been heated by combustion of these incondensable gases mixed with an air flow A. Methane M is preferably used to for preheating during startup phases or as makeup to maintain the temperature. Note that a single circulation pump can also be used for the two lines FR″₁ and FR″₂, with a regulation valve on each line to adjust the corresponding flows.

The installation 10 also comprises injection means in the form of a second circulating pump Ci₂ so that a second part FR″₂ of the incondensable gases flow FR″ output from the condenser 14 to the heat exchanger E of the burner 11 can be injected to form the counter current flow FC of hot gases circulating in the hot gases counter current injection duct 6.

More particularly, the burner 11, more precisely the chamber in which the burner 11 is placed, comprises a heat exchanger E in which the second part FR″₂ of the incondensable gases flow FR″ circulates, this flow being heated by the first part FR″₁ of the incondensable gases flow FR″, itself heated by its combustion with the flow of air and methane M. After passing in the burner 11, this first part of the incondensable gases flow FR″₁ is evacuated in the form of exhaust gases through the outlet EF from the burner 11 after having transferred its heat to the incondensable gases flow FR″₂ by means of the heat exchanger.

The use of incondensable gases FR″ at the burner 11 is advantageous to the extent that calculations show that the energy contained in these incondensable gases is of the order of 8 MJ/Nm³, which is enough to provide the necessary heat to the reactor 1. Nevertheless, external gas and particularly natural gas or another type of combustible gas can be added to the burner to achieve a certain margin on the power.

Obviously, the invention is not limited to the example embodiment that has just been described. An expert in the subject can make various modifications to it.

In particular, it would be possible to recover char C from the separator 12 and the burner, for example by means of the flow of air A and methane M, to inject it also into the burner 11 and add additional heat to the reactor 1.

A heat exchanger can also be placed at the horn, in other words between the separator 12 and the condenser 14, to recover heat and use it to preheat the counter current flow FC of hot gases before it enters the reaction chamber 3.

Furthermore, the char C and the pyrolysis oil H obtained can be mixed to form a slurry with a better calorific value in combustion than pyrolysis oil alone. 

1-16. (canceled)
 17. A fast pyrolysis reactor with an entrained flow of biomass organic particles, the fast pyrolysis reactor comprising: a tubular reaction chamber in which a pyrolysis reaction of particles takes place, comprising an upper part and a lower part opposite the upper part, a device for injection of particles in the upper part of the tubular reaction chamber, to form a flow of particles dropping by gravity in the tubular reaction chamber, an evacuation duct for products, comprising gases and pyrolyzed particles, originating from the pyrolysis reaction and present in the tubular reaction chamber, and a counter current hot neutral gases injection duct in the lower part of the tubular reaction chamber to form a counter current flow of hot neutral gases coming into contact with the flow of particles dropping by gravity, so as to generate a fast pyrolysis reaction of the particles, a temperature of the hot neutral gases being between 500 and 600° C., and a diameter of the particles being between 200 μm and 1 mm.
 18. The fast pyrolysis reactor according to claim 17, wherein the evacuation duct opens up in the upper part of the tubular reaction chamber to evacuate products derived from the pyrolysis reaction in the tubular reaction chamber, since the products migrate to the upper part of the tubular reaction chamber.
 19. The fast pyrolysis reactor according to claim 17, wherein the diameter of the particles is between 200 μm and 800 μm.
 20. The fast pyrolysis reactor according to claim 17, wherein the device for injection of particles comprises: a reservoir of particles, comprising particles and located outside the tubular reaction chamber, a tubular injector of particles located in the upper part of the tubular reaction chamber, and means of transporting particles originating from the reservoir to the tubular injector.
 21. The fast pyrolysis reactor according to claim 20, wherein a diameter of the tubular injector is less than a diameter of the tubular reaction chamber.
 22. The fast pyrolysis reactor according to claim 20, wherein the means of transporting the particles comprise a worm screw system or a vibrating belt system.
 23. The fast pyrolysis reactor according to claim 17, further comprising: means of injecting an entrainment gas in the upper part of the tubular reaction chamber, to improve the injection of particles into the tubular reaction chamber.
 24. An installation for fast pyrolysis of biomass organic particles, comprising: the fast pyrolysis reactor according to claim 17, a burner upstream from the fast pyrolysis reactor, configured to produce hot neutral gases circulating in the counter current hot neutral gases injection duct, a separator downstream from the fast pyrolysis reactor, configured to enable separation of pyrolytic coke and a flow of condensable and incondensable gases, and a condenser downstream from the separator, configured to enable separation of pyrolytic oil and the flow of incondensable gases.
 25. The installation according to claim 24, further comprising: means of injection of a first part of an incondensable gases flow output from the condenser into a boiler after heating by combustion of the first part of the incondensable gases flow.
 26. The installation according to claim 24, further comprising: means of injecting a second part of an incondensable gases flow output from the condenser to a heat exchanger of the burner to form the hot neutral gases circulating in the counter current hot neutral gases injection duct, heat being produced from the burner supplied by a first part of the incondensable gases flow.
 27. A process for fast pyrolysis of biomass organic particles in the fast pyrolysis reactor according to claim 17, the process comprising: counter current injecting hot neutral gases into the tubular reaction chamber of the fast pyrolysis reactor in a direction opposite to a direction of particles dropping by gravity, on which the fast pyrolysis reaction takes place.
 28. The process according to claim 27, further comprising: heating hot neutral gases circulating in the counter current hot neutral gases injection duct and/or forming the hot neutral gases circulating in the counter current hot neutral gases injection duct, with an incondensable gases output from the condenser, wherein the process is implemented with a fast pyrolysis installation and the fast pyrolysis installation comprises: the fast pyrolysis reactor; a burner upstream from the fast pyrolysis reactor, configured to produce hot neutral gasses circulating in the counter current hot neutral gases injection duct, a separator downstream from the fast pyrolysis reactor, configured to enable separation of pyrolytic coke and a flow of condensable and incondensable gases; and a condenser downstream from the separator, configured to enable separation of pyrolytic oil and the flow of incondensable gases.
 29. The process according to claim 27, further comprising: injecting an entrainment gas into the tubular reaction chamber of the fast pyrolysis reactor, to improve injection of particles into the tubular reaction chamber.
 30. The process according to claim 27, further comprising: adding heat with pyrolytic coke as fuel.
 31. The process according to claim 27, further comprising: placing a heat exchanger between the separator and the condenser to enable heat recovery.
 32. The process according to claim 27, further comprising: producing a fuel with pyrolytic coke mixed with pyrolytic oil. 